Automatic stop for elevators.



P. L; IVIANLET.

AUTOMATIC STOP FOR ELEVATORS.

APPLICATION FILED SEPT-27, I91 I.

Patented Oct. 26, 1915.

I; YEW/655% Ewen- A win/76a PETER L. MANLIET, OF ST. PAUL,IVIIN'NESO'Ll-L.

AUTOMATIC sror non ELE ATORS.

Application filedSeptember 27, 1911.

To all whom it may concern:

Be it known that I, PETER L. MANLET, a citizen of the United States,residing at St. Paul, in the county of Ramsey and State of Minnesota,have invented a new and useful Improvement in Automatic Stops forElevators, of which the following is a specification.

My invention relates to improvements in automatic stops for elevatorsand its principal object is to provide a positive means for throwing offthe power operating the elevator when the elevator car or thecounterweights connected with it are carried beyond a predeterminedpoint in their respective guide tracks.

It frequently happens that an elevator operator is unable to shut oflhis power in time to prevent the car from rising too high in theelevator shaft, damaging the car and shaft and tending to break theelevator cable through the momentum of the counterweights. In a similarway the car may require automatic stopping at the bottom of its path toprevent damage to the car and counterweights. Numerous devices are inuse intended to apply brakes to the elevator car when it passes beyondits upper or lower limits, but which are frequently slow to operate orentirely ineflective. The device which I have invented operatespositively and instantly to out 01f the power operating the elevator andutilizes the electric power most efliciently to brake the motor.

In the drawings with which I have illustrated my invention and whichform part of my specification, Figure 1 is a view of an elevatorconnected by my device with a main line switch and illustrating the useof a spring; Fig. 2 is a diagrammatic view illustrating the applicationof my device to a magnetic brake by means of a three pole switch; Fig. 3is a diagrammatic view illustrating my device in connection with anarmature brake, and Fig. 4 is an elevation of the switch shown in Fig.3.

In Fig. 1 I have illustrated a main curcuit switch A supplyingpower tothe motor B shown in Fig. 2 operating an elevator car E which moves inthe car track C. A counterweight guide D is shown in which slidethecounterweights 2 connected to the elevator car in the ordinary mannerby cables 3. The 'des D are formed with grooves 4 carrying theends ofthe counter-Wei hts 2. The track also has a groove 5 or equivalentSpecification of Letters Patent.

Patented @ct. 26, 1915.

Serial no. 651,628.

' tremity-of'the path of the elevator car and carrying a flexible cordor chain 7 connect ing with a similar peg 6 in the groove 4 of theguides D. Pegs 6 are similarly positioned in the grooves 4 and 5 at thelower limit of the pathof the elevator car and counterweight andconnected by a chain 7 with a chainS which extends vertically and haspulleys 9 at its extremities running freely in the loops of the chains 7and conmeeting them in such a way that the releasing of any peg 6produces slack in the chain 8. The motor B' has a friction wheel 10 inconnection with it and brake arms 11 pivoted on a support 12 to operatethe band brake 13 on the friction wheel 10 to stop the elevator carconnected with it. The brake arms 11 are operated by solenoids 14 andopposed springs 15 mounted on them, the

solenoids 14 normally holding the band brake 13 out of contactwith thefriction wheel 10 and the springs 15 tending to tighten the brake on thewheel when the solenoids become inoperative.

Referring to Fig. 2 the switch A has connected with it main lineconductors 16 and conductors 17 connecting the motor B and the solenoids14 in parallel with each other and in series with the controller 18which is positioned in the elevator car. A chain 19 connects with aspring 20, passes between suitable pulleys 21 and terminates in a pulley22 running freely on the chain 8. The

chain 19 holds the spring in tension and released by the breaking of anyone of the pegs 6 and contracts. The opening of the switch A breaks thecircuits through the conductors 16 and 17 thus stopping the applicationof power to the motor B and applying the brake to the friction wheel 10.

In Figs. 3 and 4 I have illustrated an alternative construction of myinvention in which the main line conductors 16 connect Wil iliary blade31 attached to one of the blades 30. In the closed position of theswitch the current passes through conductors 32, 33 and 34 and theresistance 35. is open the main line circuit is broken and the motor Brotating under its own momentum generates current. The blade'31 makescontact with the conductor 36 closing the circuit from the motor throughconductors 33, 35, 36 and 32, producing an armature brake stopping theaction of the motor almost instantly. It is evident that a suitableweight may be used in place of the spring 20 described and that otherpower means besides the electric power described in the specificationmay be used in connection with the electrically operated brake mechanismshown.

In accordance with the patent statutes I have described the principlesof operation of my invention together with the apparatus which I nowconsider to represent the best embodiment thereof but I desire to haveit understood that the construction shown is only illustrative and thatthe invention can be carried out by other means and applied to usesother than those above set forthwithin the scope of the followingclaims; I

Having described my invention, what- I claim as new and desire toprotect by Letters Patent is 1. In adevice of the class set forth, anelevator car operable in a fixed path, an electric motor adapted tooperate said car, a brakefor said motor, means for'operating said brake,resilient means arranged to urge the operating means into position tocause the setting of said brake, and frangible means holding saidresilient means under stress and the operating means inactive andpositioned in a path to be broken by said car and to release theresilient means when the car moves beyond its normal travel.

When the switch I 2. In a device of the class set forth, an elevator caroperable in a predetermined path of travel, a frangible stop positionedin the path of said car, a motor adapted to operate said car, a switchadapted to control said motor, means for connecting said Stop and switchto operate the latter when said stop is broken by said car moving beyondits normal travel, and an electric brake connected with said switch andadapted to be automatically operated by the opening of said switch.

3. In a device of the class set forth, a guideway, an elevator caroperating in said guideway, an electric motor adapted to opcrate saidcar, frangible means positioned in said guideway in the path of said caradjacent the limit of its normal travel, a brake for said car, means forsetting said brake, electric means for holding said brake out ofoperation, a source of power connected with said electric means, meansfor disconnecting said electric means from said source of power, and aconnection between said frangible means and said means for disconnectingsaid power, whereby upon the breaking of said frangible means by saidcar said brake is adapted to stop said car.

4. In a device of the classset forth, an elevator car movable through anormal path of travel, means for operating said car, a friction brake onsaid operating means, a solenoid mounted in connection with said brakeadapted when energized to hold said brake out of operation, anelectrical switch connected with said solenoid, and a frangible stop inconnection with said car adapted to be broken when said car passes alimit of its normal travel and cause the opening of said switch andsetting of said brake.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

PETER L. MANLET. Witnesses:

H. L. FISCHER, PAUL S. SMITH.

